Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Year	$ 2,449	$ 627	$ 245
Additions Charged to Operations	86	1,936	439
Deductions From Reserves	2,318	114	57
Balance At End of Year	217	2,449	627
Warranty:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Year	2,244	2,329	1,525
Additions Charged to Operations	1,345	5,055	6,261
Deductions From Reserves	2,393	5,140	5,457
Balance At End of Year	1,196	2,244	2,329
Deferred Tax Asset Valuation Allowance:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Year	79,458	63,881	36,395
Additions Charged to Operations	11,316	15,577	27,486
Deductions From Reserves	0	0	0
Balance At End of Year	90,774	79,458	63,881
Sales Returns and Allowances:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Year	727	911	545
Additions Charged to Operations	0	196	497
Deductions From Reserves	572	380	131
Balance At End of Year	$ 155	$ 727	$ 911